Network-assisted peer discovery

ABSTRACT

Techniques for performing network-assisted peer discovery to enable peer-to-peer (P2P) communication are described. In one design, a device registers with a network entity (e.g., a directory agent) so that the presence of the device and possibly other information about the device can be made known to the network entity. The network entity collects similar information from other devices. The device sends a request to the network entity, e.g., during or after registration. The request includes information used to match the device with other devices, e.g., information about service(s) provided by the device and/or service(s) requested by the device. The directory agent matches requests received from all devices, determines a match between the device and at least one other device, and sends a notification to perform peer discovery. The device performs peer discovery in response to receiving the notification from the network entity.

The present application is a division of U.S. patent application Ser.No. 13/085,306 filed on Apr. 12, 2011 entitled “METHOD AND APPARATUSTHAT FACILITATES NETWORK ASSISTED DISCOVERY IN PEER-TO-PEER SYSTEMS,”now U.S. Pat. No XX,XXX,XXX incorporated herein by reference in itsentirety that claims priority to provisional U.S. Application Ser. No.61/324,606, entitled “METHOD AND APPARATUS THAT FACILITATES NETWORKASSISTED DISCOVERY IN PEER-TO-PEER SYSTEMS,” filed Apr. 15, 2010, andprovisional U.S. Application Ser. No. 61/360,705, entitled“NETWORK-ASSISTED PEER DISCOVERY,” filed Jul. 1, 2010, both incorporatedherein by reference in their entirety.

BACKGROUND

I. Field

The present disclosure relates generally to communication, and morespecifically to techniques for supporting peer-to-peer (P2P)communication.

II. Background

Wireless communication networks are widely deployed to provide variouscommunication content such as voice, video, packet data, messaging,broadcast, etc. These wireless networks may be multiple-access networkscapable of supporting multiple users by sharing the available networkresources. Examples of such multiple-access networks include CodeDivision Multiple Access (CDMA) networks, Time Division Multiple Access(TDMA) networks, Frequency Division Multiple Access (FDMA) networks,Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA)networks. A wireless communication network may also be referred to as awide area network (WAN).

A wireless communication network may include a number of base stationsthat can support communication for a number of devices. A device maycommunicate with a base station via the downlink and uplink. Thedownlink (or forward link) refers to the communication link from thebase station to the device, and the uplink (or reverse link) refers tothe communication link from the device to the base station. The devicemay also be able to communicate peer-to-peer with other devices. It maybe desirable to efficiently support P2P communication between devices.

SUMMARY

Techniques for performing network-assisted peer discovery to enable P2Pcommunication are described herein. In one design, for network-assistedpeer discovery, a device may register with a network entity (e.g., adirectory agent) so that the presence of the device and possibly otherinformation about the device can be made known to the network entity.The network entity may collect similar information from other devices.The network entity may inform the device when other devices of interestmay be within the vicinity of the device. The device may then performpeer discovery when informed by the network entity instead of all thetime, which may reduce power consumption, extend battery life, andprovide other benefits.

In one design, a first device may perform registration with a networkentity (e.g., a directory agent) for assistance for peer discovery. Forregistration, the first device may send identification information,location information, service information, and/or other information forthe first device to the network entity. The first device may send arequest to the network entity, e.g., during or after registration. Therequest may include information used to match the first device withother devices, e.g., information indicative of service(s) provided bythe first device and/or service(s) requested by the first device. Thefirst device may thereafter receive a notification from the networkentity to perform peer discovery. The notification may be generated bythe network entity based on a match between the first device and atleast one other device. The match may be determined based on the requestfrom the first device and requests from other devices. The first devicemay perform peer discovery in response to receiving the notificationfrom the network entity. The first device may perform peer discovery by(i) transmitting a proximity detection signal to enable other devices todetect the first device and/or (ii) detecting proximity detectionsignals from other devices. The notification may include pertinentinformation that may help reduce the amount of time taken to performpeer discovery.

Various aspects and features of the disclosure are described in furtherdetail below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a wireless communication network.

FIG. 2 shows communication between two devices, a base station, and adirectory agent for network-assisted peer discovery.

FIG. 3 shows a message flow for network-assisted peer discovery.

FIG. 4 shows a process for performing network-assisted peer discovery.

FIG. 5 shows a process for supporting network-assisted peer discovery.

FIG. 6 shows a process for performing peer discovery.

FIG. 7 shows a process for supporting peer discovery.

FIG. 8A shows a block diagram of a design of a device.

FIG. 8B shows a block diagram of a design of a base station.

FIG. 8C shows a block diagram of a design of a directory agent.

FIG. 9 shows a block diagram of another design of a device, a basestation, and a directory agent.

DETAILED DESCRIPTION

The techniques described herein may be used for various wirelesscommunication networks such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA andother wireless networks. The terms “network” and “system” are often usedinterchangeably. A CDMA network may implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includesWideband CDMA (WCDMA), Time Division Synchronous CDMA (TD-SCDMA), andother variants of CDMA. cdma2000 covers IS-2000, IS-95 and IS-856standards. A TDMA network may implement a radio technology such asGlobal System for Mobile Communications (GSM). An OFDMA network mayimplement a radio technology such as Evolved UTRA (E-UTRA), Ultra MobileBroadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20,Flash-OFDM®, etc. UTRA and E-UTRA are part of Universal MobileTelecommunication System (UMTS). 3GPP Long Term Evolution (LTE) andLTE-Advanced (LTE-A), in both frequency division duplexing (FDD) andtime division duplexing (TDD), are new releases of UMTS that use E-UTRA,which employs OFDMA on the downlink and SC-FDMA on the uplink. UTRA,E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from anorganization named “3rd Generation Partnership Project” (3GPP). cdma2000and UMB are described in documents from an organization named “3rdGeneration Partnership Project 2” (3GPP2). The techniques describedherein may be used for the wireless networks and radio technologiesmentioned above as well as other wireless networks and radiotechnologies.

FIG. 1 shows a wireless communication network 100, which may be an LTEnetwork or some other wireless network. Wireless network 100 may includea number of base stations and other network entities. For simplicity,only three base stations 110 a, 110 b and 110 c, one network controller130, and a directory agent 140 are shown in FIG. 1. A base station maybe an entity that communicates with the devices and may also be referredto as a Node B, an evolved Node B (eNB), an access point, etc. Each basestation 110 may provide communication coverage for a particulargeographic area and may support communication for the devices locatedwithin the coverage area. To improve network capacity, the overallcoverage area of a base station may be partitioned into multiple (e.g.,three) smaller areas. Each smaller area may be served by a respectivebase station subsystem. In 3GPP, the term “cell” can refer to a coveragearea of a base station and/or a base station subsystem serving thiscoverage area, depending on the context in which the term is used. In3GPP2, the term “sector” or “cell-sector” can refer to a coverage areaof a base station and/or a base station subsystem serving this coveragearea. For clarity, 3GPP concept of “cell” is used in the descriptionherein.

Network controller 130 may couple to a set of base stations and mayprovide coordination and control for these base stations. Networkcontroller 130 may be a single network entity or a collection of networkentities. Network controller 130 may communicate with the base stationsvia a backhaul. The base stations may also communicate with one another,e.g., directly or indirectly via wireless or wireline backhaul.Directory agent 140 may be a separate network entity and may be coupledto network controller 130 (as shown in FIG. 1) and/or other networkentities. Directory agent 140 may also be part of a base station, ornetwork controller 130, or some other network entity (not shown in FIG.1). Directory agent 140 may support peer discovery by devices, asdescribed below. Directory agent 140 may also be referred to by othernames.

Devices 120 may be dispersed throughout the wireless network, and eachdevice may be stationary or mobile. A device may also be referred to asa user equipment (UE), a user device, a mobile station, a terminal, anaccess terminal, a subscriber unit, a station, etc. A device may be acellular phone, a personal digital assistant (PDA), a wireless modem, awireless communication device, a handheld device, a laptop computer, acordless phone, a wireless local loop (WLL) station, a smart phone, anetbook, a smartbook, a tablet, a peripheral device (e.g., a printer),etc. A device may communicate with a base station in a wireless network.A device may also communicate peer-to-peer with other devices. In theexample shown in FIG. 1, devices 120 x and 120 y may communicatepeer-to-peer, and remaining devices 120 may communicate with basestations. Devices 120 x and 120 y may also be capable of communicatingwith base stations, e.g., when not engaged in P2P communication orpossibly concurrent with P2P communication. P2P communication may beused to offload data traffic in order to reduce congestion on radiointerface as well as a core network.

In the description herein, WAN communication refers to communicationbetween a device and a base station, e.g., for a call with a remotestation such as another device. P2P communication refers to directcommunication between two or more devices, without going through a basestation. Peer discovery refers to a process to detect other devices by adevice.

One challenge in P2P communication is discovery/detection of peerdevices of interest within a particular range, e.g., within radiofrequency (RF) range. Devices that can and/or desire to communicatepeer-to-peer may perform peer discovery autonomously. For autonomouspeer discovery, a device may occasionally (e.g., periodically) transmita proximity detection signal (PDS) to announce its presence and toenable other devices to detect the device. Alternatively oradditionally, the device may detect other devices near its proximitybased on proximity detection signals transmitted by these other devices.A proximity detection signal may also be referred to as a peer detectionsignal, a peer discovery signal, etc. A proximity detection signal maycomprise a pilot and may carry identification information for atransmitter of the proximity detection signal and/or other information.A pilot is a signal that is known a priori by a transmitter and areceiver and may also be referred to as a reference signal, a preamble,etc.

A device may occasionally transmit and/or receive proximity detectionsignals for autonomous peer discovery, even when no other devices may beinterested in communicating with the device. This may result insignificant battery power consumption by the device, which may degradestandby battery life of the device.

In an aspect, network-assisted peer discovery may be used to aid devicesperform peer discovery. In one design, for network-assisted peerdiscovery, a device may register with a network entity (e.g., adirectory agent) so that the presence of the device and possibly otherinformation about the device can be made known to the network entity.The network entity may collect similar information from other devices.The network entity may inform the device when other devices of interestmay be within the vicinity of the device. The device may then performpeer discovery when informed by the network entity instead of all thetime, which may reduce power consumption for peer discovery, extendbattery life of the device, and provide other benefits.

FIG. 2 shows communication between two devices 120 x and 120 y anddirectory agent 140 via base station 110 a for network-assisted peerdiscovery. Devices 120 x and 120 y may communicate with directory agent140 via the same base station 110 a or via different base stations fornetwork-assisted peer discovery. Devices 120 x and 120 y may alsocommunicate with base station 110 a for WAN communication and also forscheduling of P2P communication. Devices 120 x and 120 y may transmitand receive proximity detection signals for peer discovery and may alsocommunication peer-to-peer. Base station 110 a may be a serving basestation of device 120 x and/or 120 y. Directory agent 140 may assistdevices 120 x and 120 y with peer discovery.

FIG. 3 shows a flow diagram of a design of a process 300 fornetwork-assisted peer discovery. Device 120 x may register itself withdirectory agent 140 (or some other designated network entity) based onsome trigger (step 1). For example, device 120 x may register withdirectory agent 140 upon entering WAN coverage, e.g., upon detecting amacro cell in wireless network 100. Device 120 x may also register withdirectory agent 140 to request one or more services, to advertise one ormore services, to query for peer devices near the vicinity of device 120x, etc. Directory agent 140 may or may not be part of wireless network100.

Device 120 x may provide pertinent information to directory agent 140 aspart of P2P registration. In one design, device 120 x may provideidentification information identifying device 120 x, service informationidentify one or more services offered and/or requested by device 120 x,location information for device 120 x, etc. The identificationinformation may comprise a device identity (ID) of device 120 x. Adevice ID may have a suitable length (e.g., 12 bits or some other numberof bits) to ensure uniqueness with sufficiently high probability. Theservice information may include one or more service IDs for one or moreservices offered by device 120 x and/or one or more services requestedby device 120 x. A number of services may be defined/supported, and eachservice may be assigned a different service ID to identify that service.A group of related services may also be defined and assigned a serviceID. A ‘wildcard’ service may also be defined and may cover all services.A service ID may be a string or an index of a suitable length (e.g., 12bits or some other number of bits) that can uniquely identify a service,a group of services, or all services. The location information mayprovide a coarse or an accurate geographical location of device 120 x.For example, the location information may provide a tracking area ofdevice 120 x or the location of a serving base station of device 120 xas a coarse location of device 120 x. The location information may alsoprovide an accurate location estimate for device 120 x, which may beobtained based on a Global Navigation Satellite System (GNSS) such asGlobal Positioning System (GPS).

Device 120 x may perform P2P registration to advertise its servicesand/or to obtain services. In one design, device 120 x may send a P2Prequest at the time of P2P registration (step 2). The P2P request mayindicate one or more services offered by device 120 x and/or one or moreservices requested by device 120 x. For example, device 120 x may run aparticular P2P gaming application and may send a P2P request indicatinga desire to seek partners for a particular game. A P2P request may alsobe for a wildcard service, which may imply that device 120 x issearching for all available services.

In one design, device 120 x may submit a new P2P request or update anexisting P2P request at any time after P2P registration. An updated P2Prequest may be sent due to various reasons such as a change in theoperating status of device 120 x, a change in the geographical locationof device 120 x, a change in the battery status of device 120 x, etc. Achange in the battery status may preclude device 120 x from offeringcertain services advertised earlier and/or obtaining certain servicesrequested earlier.

In general, a P2P request may be sent explicitly by device 120 x or maybe implicit and not sent. A P2P request may also be a transient requestor a persistent request. A transient request may be valid for apredetermined period of time, which may typically be a short duration. Apersistent request may be valid for an extended time period orindefinitely until it is explicitly canceled by a requesting device orremoved by directory agent 140 due to some trigger. In one design, a P2Prequest may be associated with a time period in which the P2P request isvalid and may be discarded after this time period.

Directory agent 140 may perform P2P registration of devices and maymaintain a list of active P2P requests from these devices. Directoryagent 140 may perform request matching, examine the P2P requests fromdifferent devices, and identify devices with matching P2P requests (step3). Matching may be performed based on various criteria such as theservices being offered, the services being requested, the capabilitiesof the devices, the locations of the devices, etc. For example, a matchmay be declared between devices 120 x and 120 y due to device 120 xoffering a service that is requested by device 120 y, or vice versa. Amatch may also require the two devices to be within RF range of oneanother, which may be determined based on the location informationprovided by the devices during P2P registration.

If a match is found for device 120 x, then directory agent 140 may senda notification of the match to device 120 x (step 4 a). Directory agent140 may also notify device 120 y, which may have performed P2Pregistration with directory agent 140 earlier and may be part of thematch for device 120 x (step 4 b). The match notifications may informdevices 120 x and 120 y to initiate peer discovery, if needed.

Devices 120 x and 120 y may perform peer discovery in response toreceiving the match notifications from directory agent 140 (step 5).Peer discovery may refer to the overall process to detect the presenceof other devices, which may include steps 1 to 5 in FIG. 3 fornetwork-assisted peer discovery. Peer discovery may also refer to theactual detection of other devices, which may include only step 5 in FIG.3. The actual detection of other devices in step 5 may also be referredas PHY discovery, RF discovery, etc.

Peer/PHY discovery may be performed to determine whether two or morematched devices are in sufficient RF proximity in order to establish adirect data connection without involving a wireless network. Detectionof RF proximity may also be useful for other purposes even if directdata communication is not desired. For example, in large open spaces, RFproximity may be considered a good approximation of geographicalproximity In one design of peer/PHY discovery, device 120 x may transmita proximity detection signal to enable device 120 y to detect device 120x. Device 120 y may detect the proximity detection signal from device120 x. Alternatively or additionally, device 120 y may transmit aproximity detection signal to enable device 120 x to detect device 120y. Device 120 x may then detect the proximity detection signal fromdevice 120 y.

In one design, devices 120 x and 120 y may perform peer/PHY discoverywithout assistance from the network. For example, devices 120 x and 120y may have a default set of proximity detection signals to use forpeer/PHY discovery. In one design, a proximity detection signal mayinclude a device ID that identifies a device transmitting the proximitydetection signal. A proximity detection signal may also include otherinformation such as a service ID that identifies one or more servicesbeing offered or requested.

In another design, devices 120 x and 120 y may perform peer/PHYdiscovery with assistance from the network (not shown in FIG. 3). Inthis design, directory agent 140 may notify serving base station 110 aabout the match between devices 120 x and 120 y to enable base station110 a to assist these devices perform peer/PHY discovery. Base station110 a may determine one or more parameters for peer/PHY discovery suchas (i) which particular pilot sequence to use for a proximity detectionsignal, (ii) which device should transmit the proximity detection signaland which device should receive the signal, (iii) time and frequencyresources to use to transmit the proximity detection signal, (iv)transmit power level of the proximity detection signal, and/or (v) otherparameters. These parameters may be selected by considering thelong-term channel quality of devices 120 x and 120 y, so that lowerinterference can be observed in detection of the proximity detectionsignal, which may increase discovery range.

In one design, each device in a group of matched devices may transmit aproximity detection signal and also detect proximity detection signalsfrom other devices in the group. Each device may alternate between (i) atransmit state in which the device transmits its proximity detectionsignal and (ii) a listen/receive state in which the device detectsproximity detection signals from other devices. In another design, onedevice in a group of matched devices may be requested to transmit aproximity detection signal, and all other devices in the group may berequested to detect the proximity detection signal. In general, thenumber of devices to transmit proximity detection signals may bedepending on the number of devices and the type of devices associatedwith a match. The goal of peer discovery may be to maximize theprobability of peer detection while maintaining energy efficiency. Inany case, peer/PHY discovery may allow devices 120 x and 120 y todetermine whether they are within RF proximity and can establish adirect data connection.

In one design, device 120 x may measure the received signal strength ofthe proximity detection signal from device 120 y (step 6). The receivedsignal strength may be measured by correlating a received signal atdevice 120 x with an expected pilot sequence for the proximity detectionsignal transmitted by device 120 y. In one design, device 120 x may alsomeasure a downlink pilot from its serving base station 110 a. Device 120x may send a pilot measurement report and possibly other information toserving base station 110 a (step 7). The pilot measurement report mayinclude (i) the received signal strength of the proximity detectionsignal from device 120 y and/or (ii) the received signal strength of thedownlink pilot from serving base station 110 a. The other informationmay include timing information for device 120 y, e.g., a timing offsetof a correlation peak for the proximity detection signal from device 120y with respect to the downlink timing of serving base station 110 a.Alternatively or additionally, device 120 y may measure the receivedsignal strength of the proximity detection signal from device 120 xand/or the downlink pilot from base station 110 a and may send a pilotmeasurement report to base station 110 a (not shown in FIG. 3). Ingeneral, any device that receives a proximity detection signal fromanother device may measure the received signal strength of the proximitydetection signal and send a pilot measurement report.

In one design, serving base station 110 a (or some other designatednetwork entity) may select P2P communication or WAN communication fordevices 120 x and 120 y (step 8). For example, P2P communication may beselected if the received signal strength of the proximity detectionsignal measured by device 120 x or 120 y indicates that the quality ofthe wireless channel between devices 120 x and 120 y is sufficientlygood, e.g., if the received signal strength exceeds a threshold.Conversely, WAN communication may be selected for devices 120 x and 120y if the received signal strength is insufficient, e.g., below thethreshold. In one design, even if P2P communication is selected, a WANconnection may be established for devices 120 x and 120 y as a backup.

Serving base station 110 a may send a scheduling decision to devices 120x and 120 y (steps 9 a and 9 b). The scheduling decision may indicatewhether P2P communication or WAN communication is selected for devices120 x and 120 y. The scheduling decision may also convey resources touse for P2P communication or WAN communication. Devices 120 x and 120 ymay then communicate in accordance with the scheduling decision, e.g.,communicate peer-to-peer as shown in FIG. 3 (step 10).

In general, the radio technology used for peer discovery in step 5 mayor may not be the same as the radio technology used for P2Pcommunication in step 10. For example, peer discovery may be performedusing LTE whereas P2P communication may occur using Wi-Fi.

FIG. 3 shows a specific design of network-assisted peer discovery. Inthis design, the steps involving P2P request and request matching may beperformed first, and the steps involving peer/PHY discovery and pilotmeasurement reporting may be performed later.

In another design, device 120 x may first perform peer/PHY discovery todetect other devices in its vicinity. Device 120 x may then report thereceived signal strength and a device ID and/or a service ID of eachdetected device along with a P2P request to directory agent 140. Thedevice ID and/or service ID of each detected device may be obtained froma proximity detection signal transmitted by that device. The service IDof each detected device may be used by directory agent 140 to identifythe service(s) associated with that device, which may be useful forrequest matching. This design may be particularly advantageous whenthere are few active devices in the vicinity of device 120 x. In thiscase, device 120 x can attempt to discover these active devices andprovide directory agent 140 with a smaller set of candidate devices thatare known to be in RF proximity of device 120 x. Directory agent 140 maymatch the P2P request from device 120 x with the P2P requests from thedevices detected by device 120 x.

In one design, devices 120 x and 120 y may perform peer/PHY discoverywith network assistance, as described above. In this design, the network(e.g., serving base station 110 a) may provide a set of parameters touse for peer/PHY discovery. These parameters may be negotiated byneighboring base stations to provide good performance. For example,different sets of resources and/or different sets of proximity detectionsignals may be reserved for peer/PHY discovery by devices served bydifferent base stations. Each base station may then assign resources inits allocated set of resources and/or assign proximity detection signalsin its allocated set of proximity detection signals to devices withinits coverage for peer/PHY discovery. Peer/PHY discovery may be moreefficient with network assistance.

In another design, devices 120 x and 120 y may perform peer/PHYdiscovery without explicit network assistance. This may be achieved invarious manners. In one design, devices 120 x and 120 y may performpeer/PHY discovery using default parameters, which may comprise a set ofdefault proximity detection signals, specific resources reserved fortransmission of proximity detection signal, etc. The default parametersfor peer/PHY discovery may be known by devices 120 x and 120 y or may bebroadcast by wireless network 100.

In another design of performing peer/PHY discovery without explicitnetwork assistance, devices 120 x and 120 y may negotiate parameters touse for peer/PHY discovery. For example, devices 120 x and 120 y mayengage in WAN communication via wireless network 100 to set up a directInternet Protocol (IP) connection with each other. Devices 120 x and 120y may communicate via this IP connection to negotiate parameters to usefor peer/PHY discovery. Devices 120 x and 120 y may then performpeer/PHY discovery based on the negotiated parameters. In this design,directory agent 140 may provide the IP addresses of matched devices 120x and 120 y, e.g., provide the IP address of device 120 x to device 120y and/or provide the IP address of device 120 y to device 120 x.

Devices 120 x and 120 y may perform peer/PHY discovery without networkassistance in other manners. RF proximity between devices 120 x and 120y may be determined by the peer/PHY discovery without explicit networkassistance.

FIG. 3 shows a design of network-assisted communication. In this design,the network (e.g., serving base station 110 a) may select P2Pcommunication or WAN communication for devices 120 x and 120 y and mayalso schedule the devices for WAN communication or P2P communication(e.g., assign resources to use for communication). In another design,P2P communication may be established without explicit networkassistance. For example, wireless network 100 may set aside somesemi-statically reserve resources for P2P communication. Devices 120 xand 120 y may negotiate with each other for P2P communication (e.g.,select resources to use for P2P communication). Devices 120 x and 120 ymay use the network only to establish an IP connection to facilitateexchange of messages for negotiation.

In general, all or some of the steps in FIG. 3 may be performed fornetwork-assisted peer discovery and P2P communication. For example,steps 1, 3 and 4 a/4 b may be performed to support network-assisted peerdiscovery. Devices 120 x and 120 y may then perform peer/PHY discoveryin step 5 and initiate P2P communication in step 10 without networkassistance.

An advantage of network-assisted peer discovery is that the devices mayperform peer/PHY discovery by transmitting and/or receiving proximitydetection signals only after a match has been detected. This may resultin significant battery savings for devices, especially when searchingfor services that may appear infrequently in time and/or may be sparselydistributed in space. The power savings may be especially beneficial forpower-limited devices. Peer/PHY discovery may be performed with orwithout further network assistance.

Directory agent 140 may support network-assisted peer discovery, performP2P registration for devices, receive P2P requests from devices, andperform request matching, as described above. In one design, directoryagent 140 may be external to wireless network 100 and may be operated bya separate entity. For example, a game developer may have a game serverthat can handle requests for one or more games with P2P capability.Directory agent 140 may be part of the game server and may operate likea search engine such as an Internet search engine. In another design,directory agent 140 may be part of wireless network 100. For example, anetwork operator providing cellular access may deploy directory agent140 in a core network to match P2P requests across differentapplications.

In one design, directory agent 140 may be used for a specificapplication. For example, an application such as Facebook may chose todeploy one common directory agent across different wireless networks tosupport the application. In another design, directory agent 140 may beused for more than one application. For example, a network operator maydeploy directory agent 140 to handle different applications supported bywireless network 100.

In the design shown in FIG. 3, network assistance may be used forpeer/PHY discovery in step 5 and scheduling for communication in step 8.A network may allocate resources for transmission of proximity detectionsignals. The network may also use pilot measurement reports to determineRF proximity between the devices and may assign resources for P2Pcommunication. One or more network entities may be designated to performthese tasks.

In another aspect, devices may perform peer discovery without networkassistance. In one design, a device may transmit a proximity detectionsignal that may include a service ID and a service request flag. Theservice ID may identify one or more services provided by the deviceand/or one or more services requested by the device. The service requestflag may indicate whether the device is (i) a server providing theservices indicated by the service ID or (ii) a client consuming theservices indicated by the service ID. The service ID may also be for a‘wildcard’ service, which may include all services. The device maytransmit the proximity detection signal occasionally (e.g.,periodically) or when triggered by an event. The event may correspond tothe device being turned on, or an application becoming active on thedevice, or a change in the location of the device, or some othercondition. Each device may listen for proximity detection signals fromother devices. Each device may obtain a service request from eachdetected proximity detection signal and may determine whether thedetected device provides the requested service(s) and/or desires theoffered service(s), as indicated by the service request. Each devicethat can provide the requested service(s) or desires the offeredservice(s) may begin transmitting its proximity detection signal, e.g.,at a more frequent rate to enable faster discovery. A device maytransmit a request for a ‘wildcard’ service to indicate that the deviceis interested in all services in its vicinity. A device that receives arequest for a ‘wildcard’ service may begin transmitting its proximitydetection signal to enable peer discovery.

FIG. 4 shows a design of a process 400 for performing network-assistedpeer discovery. Process 400 may be performed by a first device (asdescribed below) or by some other entity. The first device may performregistration with a network entity (e.g., a directory agent) forassistance for peer discovery (block 412). For registration, the firstdevice may send identification information, location information,service information, and/or other information for the first device tothe network entity.

The first device may send a request to the network entity, e.g., duringor after registration (block 414). The request may comprise informationused to match the first device with other devices, e.g., informationindicative of at least one service provided by the first device, or atleast one service requested by the first device, or a wildcard serviceindicating that the first device is requesting all available services,or some other service. The request may be (i) valid for a predeterminedperiod of time or (ii) persistent and valid until canceled by the firstdevice or removed by the network entity based on a trigger. The firstdevice may send an updated request to the network entity due to a changein operating status of the first device, or a change in the location ofthe first device, or a change in battery status of the first device, orfor some other reason.

The first device may receive a notification from the network entity toperform peer discovery (block 416). The notification may be generated bythe network entity based on a match between the first device and atleast one other device. The match may be determined based on the requestfrom the first device and requests from other devices.

The first device may perform peer discovery in response to receiving thenotification from the network entity (block 418). In one design, thefirst device may perform peer discovery only when triggered bynotifications from the network entity when network-assisted peerdiscovery is invoked, which may save battery power. In another design,the first device may autonomously perform peer discovery (e.g.,occasionally) and may also perform peer discovery when informed by thenetwork entity.

In one design, the first device may perform peer discovery bytransmitting a proximity detection signal to announce its presence andenable at least one other device to detect the first device.Alternatively or additionally, the first device may perform peerdiscovery by detecting at least one proximity detection signaltransmitted by at least one other device. In general, the first devicemay perform peer discovery by transmitting and/or receiving proximitydetection signals.

In one design, network assistance may be used for peer discovery. Thefirst device may receive at least one parameter to use for peerdiscovery from a network and may perform peer discovery in accordancewith the at least one parameter. The at least one parameter mat indicatewhether to transmit a proximity detection signal, a particular pilotsequence to use for the proximity detection signal, time-frequencyresources to use to transmit the proximity detection signal, whether toreceive proximity detection signals, time-frequency resources on whichto receive proximity detection signals, some other parameter, or acombination thereof.

In another design, peer-to-peer negotiation may be used to aid peerdiscovery. In one design, the first device may receive an address of asecond device from the network entity. The first device may establish aconnection with the second device via a network based on the address ofthe second device. The first device may then communicate with the seconddevice via the connection to determine at least one parameter to use forpeer discovery. The first device may perform peer discovery inaccordance with the at least one parameter.

In one design, network assistance may be used to determine which type ofcommunication to employ. The first device may detect the second devicevia peer discovery and may measure the received signal strength of aproximity detection signal from the second device. The first device mayreport the received signal strength of the second device to the network(e.g., to a serving base station of the first device). The first devicemay receive an indication to use P2P communication or WAN communicationbetween the first and second devices. The first device may communicatewith the second device via P2P communication or WAN communication, asconveyed by the indication.

In one design, the same radio technology may be used for both peerdiscovery and communication. In another design, different radiotechnologies may be used for peer discovery and communication. In thisdesign, the first device may perform peer discovery based on a firstradio technology and may communicate directly with the second devicebased on a second radio technology, which may be different from thefirst radio technology.

FIG. 5 shows a design of a process 500 for supporting peer discovery.Process 500 may be performed by a network entity (e.g., a directoryagent) as described below or by some other entity. The network entitymay perform registration for a first device to provide assistance forpeer discovery (block 512). The network entity may receiveidentification information, location information, service information,and/or other information for the first device as part of registration.

The network entity may receive a request from the first device, e.g.,during or after registration (block 514). The request may compriseinformation used to match the first device with other devices. Thenetwork entity may retain the request (i) for a predetermined period oftime or (ii) until the request is canceled by the first device or isremoved by the network entity based on a trigger. The network entity mayalso receive an updated request from the first device due to a change inoperating status of the first device, or a change in the location of thefirst device, or a change in battery status of the first device, etc.

The network entity may determine whether to inform the first device toperform peer discovery (block 516). The network entity may send anotification to the first device in response to a decision to inform thefirst device to perform peer discovery (block 518). In one design, thenetwork entity may perform request matching to match requests from aplurality of devices including the first device. The network entity maydetermine a match between the first device and at least one other devicebased on the requests from the first device and the at least one otherdevice, location information for the devices, etc. The network entitymay determine to inform the first device to perform peer discovery basedon the match between the first device and the at least one other device.

In one design, to support peer discovery, the network entity may send anaddress of a second device (which may be part of the match) to the firstdevice. The first device may establish a connection with the seconddevice via a network based on the address of the second device. Thefirst device may then communicate with the second device to determine atleast one parameter to use for peer discovery.

In one design, the network entity may be external to a network and mayperform registration and request matching for devices in one or morenetworks. In another design, the network entity may be part of a networkand may perform registration and request matching for devices in thenetwork. In one design, the network entity may provide assistance forpeer discovery for a particular application. In another design, thenetwork entity may provide assistance for peer discovery for devices fora plurality of applications.

FIG. 6 shows a design of a process 600 for performing peer discovery.Process 600 may be performed by a first device (as described below) orby some other entity. The first device may perform peer discovery (block612) and may detect at least one device via peer discovery (block 614).The first device may measure received signal strength of at least oneproximity detection signal from the at least one device (block 616). Thefirst device may obtain a device ID of each of the at least one devicebased on the proximity detection signal received from that device. Thefirst device may report the received signal strength and identificationinformation for the at least one device to a network (block 618). Theidentification information may comprise the device ID of each device.

The first device may receive information related to one or more devicesamong the at least one device from the network (block 620). In onedesign, the one or more devices may match the first device, and thefirst device may perform peer discovery to detect the one or moredevices. In another design, the first device may determine whether toengage in P2P communication with any of the one or more devices based onthe information received from the network (block 622).

In one design, for network-assisted peer discovery, the first device maysend to the network a request comprising information used to match thefirst device with other devices. The first device may receive anotification to perform peer discovery from the network. Thenotification may be determined based on the request from the firstdevice and other information (e.g., the received signal strength and theidentification information for the at least one device) reported to thenetwork by the first device. The notification may be generated due to amatch between the first device and one or more other devices. The firstdevice may perform peer discovery in response to receiving thenotification from the network.

FIG. 7 shows a design of a process 700 for supporting peer/PHYdiscovery. Process 700 may be performed by a network entity, which maybe a base station, a network controller, etc. The network entity mayreceive a notification of a plurality of devices designated to performpeer discovery (block 712). The network entity may determine at leastone parameter to use for peer discovery by the plurality of devices(block 714). The at least one parameter may indicate whether to transmita proximity detection signal, or a particular pilot sequence to use forthe proximity detection signal, or time-frequency resources to use totransmit the proximity detection signal, or whether to receive proximitydetection signals, or time-frequency resources on which to receiveproximity detection signals, or some other parameter, or a combinationthereof. The network entity may send the at least one parameter to atleast one device among the plurality of devices (block 716).

In one design, the network entity may receive a pilot measurement reportfrom a first device. The pilot measurement report may comprise receivedsignal strength of a proximity detection signal from a second devicedetected by the first device via peer discovery. The network entity mayselect P2P communication or WAN communication for the first and seconddevices based on the pilot measurement report. In one design, thenetwork entity may select P2P communication if the received signalstrength is above a threshold and may select WAN communication if thereceived signal strength is below the threshold. The network entity mayalso select P2P communication or WAN communication based on othercriteria. The network entity may send an indication to use P2Pcommunication or WAN communication to the first device.

FIG. 8A shows a block diagram of a design of a device 120 u, which maybe one of the devices in FIG. 1. Within device 120 u, a receiver 812 mayreceive P2P signals transmitted by other devices for P2P communicationand downlink signals transmitted by base stations for WAN communication.A transmitter 814 may transmit P2P signals to other devices for P2Pcommunication and uplink signals to base stations for WAN communication.A module 816 may detect proximity detection signals transmitted by otherdevices for peer discovery. A module 818 may generate and transmit aproximity detection signal for peer discovery.

A module 820 may support network-assisted peer discovery and may performP2P registration with directory agent 140, generate and send P2Prequests, receive notifications, and initiate peer discovery in responseto the notifications. A module 822 may measure received signal strengthof proximity detection signals from other devices and downlink pilotsfrom base stations. Module 822 may generate pilot measurement reportscomprising the received signal strengths of devices and base stations ofinterest and may send the pilot measurement reports, e.g., to a servingbase station.

A module 824 may support P2P communication, e.g., generate and processsignals used for P2P communication. A module 826 may support WANcommunication, e.g., generate and process signals used for WANcommunication. The various modules within device 120 u may operate asdescribed above. A controller/processor 828 may direct the operation ofvarious modules within device 120 u. A memory 830 may store data andprogram codes for device 120 u.

FIG. 8B shows a block diagram of a design of a base station 110 u, whichmay be one of the base stations in FIG. 1. Within base station 110 u, areceiver 842 may receive uplink signals transmitted by UEs for WANcommunication. A transmitter 844 may transmit downlink signals to UEsfor WAN communication. A module 846 may receive pilot measurementreports from devices. A scheduler 848 may select P2P communication orWAN communication for devices based on the pilot measurement reports andmay allocate resources to the scheduled devices.

A module 850 may support WAN communication for UEs, e.g., generate andprocess signals used for WAN communication. A module 852 may supportcommunication with other network entities (e.g., other base stations,network controllers, directory agent 140, etc.) via the backhaul. Thevarious modules within base station 110 u may operate as describedabove. A controller/processor 854 may direct the operation of variousmodules within base station 110 u. A memory 856 may store data andprogram codes for base station 110 u.

FIG. 8C shows a block diagram of a directory agent 140 u, which may beone design of directory agent 140 in FIG. 1. Within directory agent 140u, a module 872 may perform P2P registration for devices seekingassistance for peer discovery. A module 874 may perform request matchingto identify devices that match other devices. A module 876 may sendnotifications to matched devices. A module 878 may support communicationwith other network entities (e.g., network controllers, base stations,etc.)

via the backhaul. A controller/processor 880 may direct the operation ofvarious modules within the directory agent. A memory 882 may store dataand program codes for the directory agent.

The modules within device 120 u in FIG. 8A, base station 110 u in FIG.8B, and directory agent 140 u in FIG. 8C may comprise processors,electronic devices, hardware devices, electronic components, logicalcircuits, memories, software codes, firmware codes, etc., or anycombination thereof.

FIG. 9 shows a block diagram of a base station 110 v, a device 120 v,and a directory agent 140 v, which may be another design of a device, abase station, and directory agent 140 in FIG. 1. Base station 110 v maybe equipped with T antennas 934 a through 934 t, and device 120 v may beequipped with R antennas 952 a through 952 r, where in general T≧1 andR≧1.

At base station 110 v, a transmit processor 920 may receive data from adata source 912 and control information (e.g., messages supporting peerdiscovery) from a controller/processor 940. Processor 920 may process(e.g., encode and modulate) the data and control information to obtaindata symbols and control symbols, respectively. Processor 920 may alsogenerate reference symbols for synchronization signals, referencesignals, etc. A transmit (TX) multiple-input multiple-output (MIMO)processor 930 may perform spatial processing (e.g., precoding) on thedata symbols, the control symbols, and/or the reference symbols, ifapplicable, and may provide T output symbol streams to T modulators(MODs) 932 a through 932 t. Each modulator 932 may process a respectiveoutput symbol stream (e.g., for OFDM, etc.) to obtain an output samplestream. Each modulator 932 may further process (e.g., convert to analog,amplify, filter, and upconvert) the output sample stream to obtain adownlink signal. T downlink signals from modulators 932 a through 932 tmay be transmitted via T antennas 934 a through 934 t, respectively.

At device 120 v, antennas 952 a through 952 r may receive the downlinksignals from base station 110 v, downlink signals from other basestations, and/or P2P signals from other devices and may provide receivedsignals to demodulators (DEMODs) 954 a through 954 r, respectively. Eachdemodulator 954 may condition (e.g., filter, amplify, downconvert, anddigitize) a respective received signal to obtain input samples. Eachdemodulator 954 may further process the input samples (e.g., for OFDM,etc.) to obtain received symbols. A MIMO detector 956 may obtainreceived symbols from all R demodulators 954 a through 954 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. A receive processor 958 may process (e.g., demodulateand decode) the detected symbols, provide decoded data for device 120 vto a data sink 960, and provide decoded control information to acontroller/processor 980.

On the uplink, at device 120 v, a transmit processor 964 may receivedata from a data source 962 and control information (e.g., messages forpeer discovery) from controller/processor 980. Processor 964 may process(e.g., encode and modulate) the data and control information to obtaindata symbols and control symbols, respectively. Processor 964 may alsogenerate reference symbols for a reference signal, a proximity detectionsignal, etc. The symbols from transmit processor 964 may be precoded bya TX MIMO processor 966 if applicable, further processed by modulators954 a through 954 r (e.g., for SC-FDM, OFDM, etc.), and transmitted tobase station 110 v, other base stations, and/or other devices. At basestation 110 v, the uplink signals from device 120 v and other devicesmay be received by antennas 934, processed by demodulators 932, detectedby a MIMO detector 936 if applicable, and further processed by a receiveprocessor 938 to obtain decoded data and control information sent bydevice 120 v and other devices. Processor 938 may provide the decodeddata to a data sink 939 and the decoded control information tocontroller/processor 940.

Controllers/processors 940 and 980 may direct the operation at basestation 110 v and device 120 v, respectively. Processor 980 and/or otherprocessors and modules at device 120 v may perform or direct process 400in FIG. 4, process 600 in FIG. 6, and/or other processes for thetechniques described herein. Processor 940 and/or other processors andmodules at base station 110 v may perform or direct process 700 in FIG.7 and/or other processes for the techniques described herein. Memories942 and 982 may store data and program codes for base station 110 v anddevice 120 v, respectively. A communication (Comm) unit 944 may enablebase station 110 v to communicate with other network entities. Ascheduler 946 may schedule devices for WAN communication and P2Pcommunication and may assign resources to the scheduled devices.

Within directory agent 140 v, a controller/processor 990 may performvarious functions to support peer discovery. Controller/processor 990may perform P2P registration for devices, receive P2P requests fromdevices, perform request matching, and provide notifications to initiatepeer discovery by matched devices. Controller/processor 990 may alsoperform process 500 in FIG. 5, process 700 in FIG. 7, and/or otherprocesses for the techniques described herein. A memory 992 may storeprogram codes and data for directory agent 140. A storage unit 994 maystore information for devices that have registered with the directoryagent, P2P requests from the devices, etc. A communication unit 996 mayenable the directory agent to communicate with other network entities.

In one configuration, apparatus 120 u or 120 v for wirelesscommunication may include means for performing registration by a firstdevice with a network entity for assistance for peer discovery, meansfor sending a request comprising information used to match the firstdevice with other devices, means for receiving a notification from thenetwork entity to perform peer discovery (e.g., due to a match with atleast one device), and means for performing peer discovery by the firstdevice in response to receiving the notification from the networkentity.

In another configuration, apparatus 140 u or 140 v for wirelesscommunication may include means for performing registration for a firstdevice by a network entity to provide assistance for peer discovery,means for receiving from the first device a request comprisinginformation used to match the first device with other devices, means fordetermining whether to inform the first device to perform peer discovery(e.g., based on requests from all devices), and means for sending anotification by the network entity to the first device in response to adecision to inform the first device to perform peer discovery.

In yet another configuration, apparatus 120 u or 120 v for wirelesscommunication may include means for performing peer discovery by a firstdevice, means for detecting at least one device by the first device viapeer discovery, means for measuring received signal strength of at leastone proximity detection signal from the at least one device, means forreporting the received signal strength and identification informationfor the at least one device to a network, means for receivinginformation related to the at least one device from the network, andmeans for determining whether to engage in P2P communication with any ofthe at least one device based on the information received from thenetwork.

In yet another configuration, apparatus 110 u or 110 v for wirelesscommunication may include means for receiving a notification of aplurality of devices designated to perform peer discovery, means fordetermining at least one parameter to use for peer discovery by theplurality of devices, and means for sending the at least one parameterto at least one device among the plurality of devices.

In an aspect, the aforementioned means may be processor 940 at basestation 110 v, or processor 980 at device 120 v, or processor 990 atdirectory agent 140 v, which may be configured to perform the functionsrecited by the aforementioned means. In another aspect, theaforementioned means may be one or more modules or any apparatusconfigured to perform the functions recited by the aforementioned means.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the disclosure herein may be implemented as electronichardware, computer software, or combinations of both. To clearlyillustrate this interchangeability of hardware and software, variousillustrative components, blocks, modules, circuits, and steps have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the disclosure herein may be implemented or performedwith a general-purpose processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with thedisclosure herein may be embodied directly in hardware, in a softwaremodule executed by a processor, or in a combination of the two. Asoftware module may reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such that theprocessor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal. In the alternative, theprocessor and the storage medium may reside as discrete components in auser terminal.

In one or more exemplary designs, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by ageneral purpose or special purpose computer. By way of example, and notlimitation, such computer-readable media can comprise RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store desired program code means in the form of instructions or datastructures and that can be accessed by a general-purpose orspecial-purpose computer, or a general-purpose or special-purposeprocessor. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

The previous description of the disclosure is provided to enable anyperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Thus, the disclosure is not intended to be limited tothe examples and designs described herein but is to be accorded thewidest scope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A method for supporting wireless communication, comprising: performing registration for a first device by a network entity to provide assistance for peer discovery; determining whether to inform the first device to perform peer discovery; and sending a notification by the network entity to the first device in response to a decision to inform the first device to perform peer discovery.
 2. The method of claim 1, wherein the performing registration comprises receiving identification information, or location information, or both for the first device by the network entity.
 3. The method of claim 1, further comprising: receiving a request from the first device by the network entity, wherein the request comprises information used to match the first device with other devices, and wherein whether to inform the first device to perform peer discovery is determined by the network entity based on the request.
 4. The method of claim 3, wherein the determining whether to inform the first device to perform peer discovery comprises performing request matching to match requests from a plurality of devices including the first device, and determining to inform the first device to perform peer discovery based on a match between the first device and at least one other device.
 5. The method of claim 4, wherein the performing request matching comprises determining the match between the first device and the at least one other device based on requests from the first device and the at least one other device.
 6. The method of claim 5, wherein the determining the match comprises determining the match based further on location information for the first device and the at least one other device.
 7. The method of claim 3, further comprising: retaining the request from the first device for a predetermined period of time by the network entity.
 8. The method of claim 3, further comprising: retaining the request from the first device until the request is canceled by the first device or is removed by the network entity based on a trigger.
 9. The method of claim 3, further comprising: receiving an updated request from the first device due to a change in operating status of the first device, or a change in location of the first device, or a change in battery status of the first device.
 10. The method of claim 1, further comprising: sending an address of a second device from the network entity to the first device, wherein the first device establishes a connection with the second device via a network based on the address of the second device.
 11. The method of claim 1, wherein the network entity provides assistance for peer discovery for a particular application.
 12. The method of claim 1, wherein the network entity provides assistance for peer discovery for devices in a network for a plurality of applications.
 13. An apparatus for wireless communication, comprising: means for performing registration for a first device by a network entity to provide assistance for peer discovery; means for determining whether to inform the first device to perform peer discovery; and means for sending a notification by the network entity to the first device in response to a decision to inform the first device to perform peer discovery.
 14. The apparatus of claim 13, further comprising: means for receiving a request from the first device by the network entity, wherein the request comprises information used to match the first device with other devices, and wherein whether to inform the first device to perform peer discovery is determined by the network entity based on the request.
 15. The apparatus of claim 14, wherein the means for determining whether to inform the first device to perform peer discovery comprises means for performing request matching to match requests from a plurality of devices including the first device, and means for determining to inform the first device to perform peer discovery based on a match between the first device and at least one other device.
 16. An apparatus for wireless communication, comprising: at least one processor configured to perform registration for a first device by a network entity to provide assistance for peer discovery, to determine whether to inform the first device to perform peer discovery, and to send a notification by the network entity to the first device in response to a decision to inform the first device to perform peer discovery.
 17. The apparatus of claim 16, wherein the at least one processor is configured to receive from the first device a request comprising information used to match the first device with other devices, and to determine whether to inform the first device to perform peer discovery based on the request.
 18. The apparatus of claim 17, wherein the at least one processor is configured to perform request matching to match requests from a plurality of devices including the first device, and to determine to inform the first device to perform peer discovery based on a match between the first device and at least one other device.
 19. A computer program product, comprising: a non-transitory computer-readable medium comprising: code for causing at least one processor to perform registration for a first device by a network entity to provide assistance for peer discovery, code for causing the at least one processor to determine whether to inform the first device to perform peer discovery, and code for causing the at least one processor to send a notification by the network entity to the first device in response to a decision to inform the first device to perform peer discovery.
 20. A method for wireless communication, comprising: performing peer discovery by a first device; detecting at least one device by the first device via peer discovery; measuring received signal strength of at least one proximity detection signal from the at least one device; reporting the received signal strength and identification information for the at least one device to a network; and receiving information related to one or more devices among the at least one device from the network.
 21. The method of claim 20, further comprising: obtaining a device identity (ID) of each of the at least one device based on a proximity detection signal received from each device, wherein the identification information comprises the device ID of each device.
 22. The method of claim 20, further comprising: sending a request from the first device to the network, the request comprising information used to match the first device with other devices; receiving a notification from the network to perform peer discovery, the notification being determined based on the request from the first device; and performing peer discovery by the first device in response to receiving the notification from the network.
 23. The method of claim 22, wherein the notification is determined based further on the received signal strength and the identification information for the at least one device reported to the network by the first device.
 24. The method of claim 20, further comprising: determining whether to engage in peer-to-peer (P2P) communication with any of the one or more devices based on the information received from the network.
 25. An apparatus for wireless communication, comprising: means for performing peer discovery by a first device; means for detecting at least one device by the first device via peer discovery; means for measuring received signal strength of at least one proximity detection signal from the at least one device; means for reporting the received signal strength and identification information for the at least one device to a network; and means for receiving information related to one or more devices among the at least one device from the network.
 26. The apparatus of claim 25, further comprising: means for sending a request from the first device to the network, the request comprising information used to match the first device with other devices; means for receiving a notification from the network to perform peer discovery, the notification being determined based on the request from the first device; and means for performing peer discovery by the first device in response to receiving the notification from the network.
 27. The apparatus of claim 25, further comprising: means for determining whether to engage in peer-to-peer (P2P) communication with any of the one or more devices based on the information received from the network.
 28. An apparatus for wireless communication, comprising: at least one processor configured to perform peer discovery by a first device, to detect at least one device by the first device via peer discovery, to measure received signal strength of at least one proximity detection signal from the at least one device, to report the received signal strength and identification information for the at least one device to a network, and to receive information related to one or more devices among the at least one device from the network.
 29. The apparatus of claim 28, wherein the at least one processor is configured to send a request from the first device to the network, the request comprising information used to match the first device with other devices, to receive a notification from the network to perform peer discovery, the notification being determined based on the request from the first device, and to perform peer discovery by the first device in response to receiving the notification from the network.
 30. The apparatus of claim 28, wherein the at least one processor is configured to determine whether to engage in peer-to-peer (P2P) communication with any of the one or more devices based on the information received from the network.
 31. A computer program product, comprising: a non-transitory computer-readable medium comprising: code for causing at least one processor to perform peer discovery by a first device, code for causing the at least one processor to detect at least one device by the first device via peer discovery, code for causing the at least one processor to measure received signal strength of at least one proximity detection signal from the at least one device, code for causing the at least one processor to report the received signal strength and identification information for the at least one device to a network, and code for causing the at least one processor to receive information related to one or more devices among the at least one device from the network.
 32. A method for supporting wireless communication, comprising: receiving a notification of a plurality of devices designated to perform peer discovery; determining at least one parameter to use for peer discovery by the plurality of devices; and sending the at least one parameter to at least one device among the plurality of devices.
 33. The method of claim 32, wherein the at least one parameter indicates whether to transmit a proximity detection signal, or a particular pilot sequence to use for the proximity detection signal, or time-frequency resources to use to transmit the proximity detection signal, or whether to receive proximity detection signals, or time-frequency resources on which to receive proximity detection signals, or a combination thereof.
 34. The method of claim 32, further comprising: receiving a pilot measurement report from the first device, the pilot measurement report comprising received signal strength of a proximity detection signal from a second device detected by the first device via peer discovery; selecting peer-to-peer (P2P) communication or wide area network (WAN) communication for the first and second devices based on the pilot measurement report; and sending an indication to use P2P communication or WAN communication to the first device.
 35. The method of claim 34, wherein the selecting P2P communication or WAN communication comprises selecting P2P communication if the received signal strength is above a threshold, and selecting WAN communication if the received signal strength is below the threshold.
 36. The method of claim 32, wherein the receiving the notification, the determining the at least one parameter, and the sending the at least one parameter are performed by a serving base station or a network controller for one or more devices among the plurality of devices.
 37. An apparatus for wireless communication, comprising: means for receiving a notification of a plurality of devices designated to perform peer discovery; means for determining at least one parameter to use for peer discovery by the plurality of devices; and means for sending the at least one parameter to at least one device among the plurality of devices.
 38. The apparatus of claim 37, further comprising: means for receiving a pilot measurement report from the first device, the pilot measurement report comprising received signal strength of a proximity detection signal from a second device detected by the first device via peer discovery; means for selecting peer-to-peer (P2P) communication or wide area network (WAN) communication for the first and second devices based on the pilot measurement report; and means for sending an indication to use P2P communication or WAN communication to the first device.
 39. An apparatus for wireless communication, comprising: at least one processor configured to receive a notification of a plurality of devices designated to perform peer discovery, to determine at least one parameter to use for peer discovery by the plurality of devices, and to send the at least one parameter to at least one device among the plurality of devices.
 40. The apparatus of claim 39, wherein the at least one processor is configured to receive a pilot measurement report from the first device, the pilot measurement report comprising received signal strength of a proximity detection signal from a second device detected by the first device via peer discovery, to select peer-to-peer (P2P) communication or wide area network (WAN) communication for the first and second devices based on the pilot measurement report, and to send an indication to use P2P communication or WAN communication to the first device.
 41. A computer program product, comprising: a non-transitory computer-readable medium comprising: code for causing at least one processor to receive a notification of a plurality of devices designated to perform peer discovery, code for causing the at least one processor to determine at least one parameter to use for peer discovery by the plurality of devices, and code for causing the at least one processor to send the at least one parameter to at least one device among the plurality of devices. 